The tuna fishing industry has been plagued in recent years with the problem of killing porpoises as the tuna fishing nets are drawn tight to catch the tuna. Porpoises are airbreathing mammals, and a certain percentage of them are entrained in the nets and are unable to escape. Despite strenuous efforts on the part of the tuna industry to spare the porpoises, including the provision of a special segment of netting which will bob beneath the water to permit the escape of most of the porpoises, a certain percentage of the animals still become panicked and cannot make their escape.
Within the few weeks preceeding the filing of this application, the tuna industry has been stricken with a crisis that threatens to drive tuna fishing boats to foreign ports and remove from San Diego one of its most coveted industries. The crisis results from the tuna industry having reached the quota of the number of porpoises it is allowed to kill for the year 1976 and thus the tuna seiners are no longer permitted to fish schools of tuna which are accompanied by porpoises. For reasons which are not entirely known, porpoises swim along with tuna schools to the extent that over 90 percent of the schools of tuna are accompanied by porpoises. Thus to fish only tuna schools unaccompanied by porpoises is clearly economically unfeasible.
The situation threatens to worsen in 1977 when the quota of porpoise deaths is halved from that of 1976, and the tuna boat captains and tuna industry are currently in the courts and in the throes of temporary restraining orders restraining the restraining orders from being enforced.
At the present time it has been the practice, at least to a certain extent, for tuna fishermen to actually dive into the water inside the tuna net as it is closed and physically throw the porpoises over the edge of the net. The few remaining porpoises which cannot escape are quite docile, and porpoises have always been known to be quite a friendly and actually happy animal. The porpoises freely acquiesce to being grabbed by the tail and the nose and being thrown over the net. However, there is a need for a more efficient way of evacuating the porpoises from within the net area and that is the point of this invention.